Two Rivers Aspen Parkland SNA

About

"Two Rivers" is a reference to the Two Rivers River, a tributary of the Red River which—despite its name—has not two but three branches. This vast, 1400-acre SNA lies within a bend of the river's South Branch in Roseau County.

This SNA protects a landscape-sized aspen parkland remnant, with extensive areas of wet and wet-mesic brush prairie, shrubby wet meadow and aspen woodland. Subtle "swell and swale" topography runs north-northwest across the area from a prominent Lake Agassiz beach ridge located near the southern margin of the site along Minnesota Highway 11.

Brush prairie is the standout feature here. Major grasses are big bluestem, Indian grass, prairie dropseed, mat muhly, prairie cordgrass, northern reed grass, and bluejoint grass. Willows, bog birch, and shrubby cinquefoil dot the wet and wet-mesic brush prairie, while better drained areas support hazel, chokecherry, and serviceberry, along with scattered bur oak. Quaking aspen increases in density toward the southwest, where it forms an aspen woodland.

This SNA offers habitat for numerous rare plant and wildlife species, including Nelson's Sparrow, Yellow Rail, northern gentian and the Powesheik skipperling butterfly (listed as an endangered species at both state and federal levels).

As SNA specialist Tyler Janke describes in an article written for SNA Nature Notes management has focused on increasing the acreage of open grassland and brush relative to aspen woodlands, using aerial photos from the 1940s and 1950s as a guide. Prescribed burns, aspen girdling and brush mowing have all been employed toward this end. The goals, notes Janke, are: 1) to reduce encroaching woody cover by 25% by the year 2024, 2) re-establish a fire and disturbance regime, and 3) maintain a diverse parkland community. Partners in this ambitious effort have included The Nature Conservancy and Conservation Corps. Says Janke, "So far, the response has been very good, with prairie species recolonizing the girdled areas."

The rare Powesheik skipper butterfly presents unique management challenges. This species of the northern tallgrass prairie is very vulnerable to loss of habitat due to woodland encroachment. But the Powesheik is also sensitive to fire and mowing, which are primary tools used by managers to prevent invasion by woody vegetation. What to do? In this case, what is most efficient may not be what's needed for the survival of the species: a combination of smaller, patchy prescribed burns done in rotation and careful seasonal timing are considered key.

This SNA lies along the route of the Waters of the Dancing Sky Scenic Byway.